This invention relates to the production of mineral fiber material, particularly of such materials as glass fibers. Specifically, the invention relates to making loose fibrous material of a type suitable for the manufacture of fiberglass products and also suitable as loose-fil insulation for blowing into attics of houses for insulation purposes.
In the manufacture of mineral fiber insulation, the mineral fibers are usually formed from molten mineral material using fiberizers. In the typical manufacturing operation the molten mineral material is introduced into a plurality of fiberizers from the forehearth and bushings of melt furnace. The fiberizers centrifuge the molten material and cause the material to be formed into fibers which are directed as a stream or veil to a collection unit.
A common apparatus and method for producing mineral fiber in continuous length blankets, packs or mats is shown in U.S. Pat. No. 4,300,931. In this patent, a stream of fibrous material is directed toward a collection surface and a flow of gases is discharged substantially parallel to the stream of fibrous material so as to expand the stream as it moves toward a collection surface, in this case, a foraminous conveyer. The flow of gases is discharged at a speed sufficiently greater than that of the stream of fibrous material so as to expand the stream as it moves toward the collection surface. Other systems have been known to use an oscillating cylinder resembling an open bottomed bucket to distribute the fibrous material rapidly from side to side of the collection surface, thereby providing relatively even distribution across the width of the insulation pack. These methods and apparatuses for producing insulation blankets or mats of fibrous web are designed such that a whole machine is dedicated to the manufacture of the desired end product.
Another desirable insulation product is loose-fil insulation or fibrous mineral material produced from blowing loose formed wool and bagging the wool without formation into a blanket or mat. U.S. Pat. No. 4,296,164 discloses a current method for the manufacture of such blowing wool. In the patent, the wool is discharged by the fiberizers onto a collection surface such as a conveyer. The resulting wool blanket is then cut or chopped into columns and the columns experience a random break-up during the bagging process. When blown into place as insulation, the columns break further into smaller prisms approximating cubes or flakes of various thicknesses. The machines which are used to manufacture the loose-fil or bagged mineral fiber insulation end product are also dedicated machines.
The need for dedicated machinery in the processes for manufacturing insulation by methods such as that shown in the '931 and '164 patents is the result of the variations in post-processing required to produce the distinct endproducts. The mineral fiber usually needs curing, cooling and drying. In the case of blown wool, additional steps such as cutting, cubing, or the hammermill are required. All of these post-processing steps require plant space for placement of the machinery and energy to operate the machinery. Thus, until the present invention, there has been little flexibility in the end-product choice for a given fiberizer line once the post-processing equipment is in place. The present invention provides the desired flexibility by offering a blown wool insulation manufacturing process and apparatus which directly intercepts the mineral fiber veil leaving the fiberizers and eliminates any need for post-processing. The invention allows a fiberizer line to simultaneously manufacture loose fibrous material for use in the manufacture of mineral fiber products and loose-fil insulation and insulation blankets or mats.
It is an object of this invention to provide an improved method and apparatus for producing loose fibrous mineral material.
It is a further object of this invention to provide a method and apparatus for directly forming loose fibrous mineral material while utilizing the same machine from which continuous mat or batt insulation is manufactured.
Yet another object of this invention is to provide a method and apparatus for producing loose-fil mineral fiber insulation while eliminating the post processing steps employed by various methods of the prior art.
A final object of the present invention is the retrieval of the mineral fibers directly from the mineral fiber veil being produced by the fiberizer and packaging of the mineral fibers for shipping.